In general, heavy construction equipment including an excavator performs various types of work at a worker-set engine RPM (for example, 1,800 to 2,500 RPM) within a predetermined range after starting an engine thereof. In addition, when a worker stops the work, the worker-set engine RPM is automatically switched to an auto idle engine RPM (for example, 1,200 RPM) at a lower level than the set engine RPM set by the worker after a predetermined elapses and when a predetermined time additionally elapses in this state, the auto idle engine RPM is automatically switched to a low idle engine RPM (for example, 800 RPM) at a lower level than the auto idle engine RPM, thereby improving fuel efficiency.
In order for the worker to perform the work again in a state of the auto idle engine RPM in which the work temporarily stops, the auto idle engine RPM needs to be increased to the worker-set engine RPM (for example, 2,000 RPM).
However, in the related art, since the auto idle engine RPM is fixed to a specific RPM, when a difference between the set engine RPM and the auto idle RPM is large, it takes a lot of time to reach the set engine RPM from the auto idle engine RPM, and as a result, the work is slowly performed, thereby degrading workability and productivity of the heavy construction equipment.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.